Shoreline property though beautified by the presence of the ocean is subject to erosion whenever storms arise which so stir the same ocean as to rage thereagainst, carrying away beach and washing away bank soil and any vegetation growing thereon. The erosion resulting from each storm is undesirable in itself, and where there are structural improvements present at and near the shoreline, such as private beach homes or popular resorts, the resulting erosion may progressively undermine the foundations thereof and thereby threaten the physical integrity of those improvements over time.
Various techniques are known to those skilled in the art of hydraulic and earth engineering for preserving shorelines or other areas subject to the erosive influence of water. So-called "armoring" techniques, such as those of Umemoto et al. U.S. Pat. No. 4,135,843, Reilly U.S. Pat. No. 5,024,560, and Risi et al. U.S. Pat. No. 5,064,313, have attempted to prevent shoreline erosion by so fortifying the shoreline with blocks, cement and the like as to form a prophylactic layer over the region of the shoreline that would otherwise be subject to the erosive effects of the moving water. Due to their weight and bulk, such armoring techniques are often difficult to install, and often result in permanent structures that cannot be taken down or put up seasonably or at will. Often, they are so configured as to prevent the enjoyment of the region of the shoreline that they overlay. Moreover, there is the difficulty of being able to adequately anchor the armor to the underlying soil, whether beach, bank or both. Water incident to the layer is accelerated in such way as to wash away beach at the beach/armor interface. The prophylactic layer itself is thereby subjected to being washed away in a severe storm.
Jetties are also known for attempting to control shoreline erosion. As is well known to those skilled in the art, each shoreline has a natural direction and flow rate in accord with which it migrates, and in the typical case, a stone or other permanent formation is build into the shore in such a manner as to form a jetty traverse the natural flow direction of the shoreline. While they have the advantageous effect of promoting local soil deposition, they suffer from the disadvantage of downstream and upstream soil erosion, and, if too many jetties are installed along a given region of shoreline, they may alter the dynamic equilibrium of the shoreline and undesirably change the shape of the beach as a whole. During storms, although they refract and thus dissipate the energy and direction of the incoming waterwaves, jetties generally have only a secondary impact insofar as storm damage control is concerned.
A third and last category of shore and bank protection techniques have attempted to control erosion by attenuating the energy, velocity, and/or direction of a potentially erosive fluid such as the sea or a river as exemplified in Schaaf et al. U.S. Pat. No. 3,479,824, Wilson U.S. Pat. No. 3,011,316, Henson U.S. Pat. No. 3,333,420, Bailey et al. U.S. Pat. No. 5,348,419, Parker U.S. Pat. No. 4,710,056 and Laier U.S. Pat. No. 4,710,057. The Shaaf et al. seawall and fence construction discloses one or more concrete panels having apertures therethrough that are pivotally hung on piles to attenuate the energy of the sea incident thereto. The Wilson breakwater and method of dissipating waves discloses spaced-apart confronting panels having louvers so arranged as to trap therebetween, and turbulently cancel, the energy of sea water that moves through the louvers The trap is installed in the body of the moving water off shore of the shoreline to be protected. The method and system for controlling the course of a river of Henson and the system for erosion control of Bailey et al. respectively disclose a slat fence and a criss-cross web defining selectable permeabilities slidably hung on piles driven into a river bed such that the criss-cross webs or slat fences are generally traverse the flow direction of the river. The criss-cross webs or slat fences cause, on the one hand, soil to deposit along the inner bank and cause, on the other hand, the thalweg of the river to be moved towards the opposite, outer bank. The method and apparatus for restoring a beach of Parker discloses one or more rows of nets installed on a shoreline to be protected such that the direction of extension of the nets is generally perpendicular to the shoreline to be protected and extends from the high tide to the low tide marks. The method and apparatus for building up beaches and shorelines of Laier discloses a system of plural, interconnected compartments disposed underwater on the seabed of the shoreline to be protected.